Torque converters are known fluid coupling devices used in automotive powertrains for connecting engine output with transmission input. The torque converter provides a torque multiplier and speed differential between the engine and transmission gearing. The fluid coupling function of the torque converter enables a smooth transmission of power during launch, shifting, as well as coasting. A torque converter clutch may or may not be employed to connect the engine to the transmission (bypassing the torque converter) and thereby improve the overall efficiency of the transmission.